1. Field of the Invention
The present invention relates to an ostomy appliance comprising a deodorising filter, in particular ostomy bags.
In connection with surgery for a number of diseases in the gastrointestinal tract a consequence is, in many cases, that the patient is left with a stoma such as a colostomy, an ileostomy or an urostomy in the abdominal wall for the discharge of the effluents or waste products of the body, which are conveyed through the colon, the ileum or the ureter. The discharge of visceral contents including intestinal gases cannot be regulated at will, and for that purpose the opening may be closed with a closure means, e.g. a tampon or a magnetic closure, or the patient will have to rely on an appliance to collect the material emerging from such opening in the form of a receiving bag which is later emptied and/or discarded at suitable times.
Ostomy appliances are well known. Such appliances may be two-piece or one-piece appliances. In both types of appliances, an adhesive wafer is attached to the wearer's skin. In case of a one-piece appliance, a receiving member or bag is attached to the adhesive wafer. In case of a two-piece appliance, the adhesive wafer forms part of a body side member and a receiving bag is attached releasably to the body side ostomy member for receiving exudates from the stoma.
When using one-piece appliances, the whole appliance, including the adhesive skin barrier securing the appliance to the skin is normally removed and replaced by a fresh appliance. When using two-piece appliances, the body side member is left in place up to several days, and only the receiving bag attached to the body side member is replaced.
The discharge of flatus, measured in volume, may exceed the discharge of solid and liquid faecal matter by many hundred percent and therefore there is usually the need for the continuous or frequent venting of the intestine or the collecting bag. Normally the flow of flatus is deodorised with a suitable filter. Commonly the active filter is powdered active carbon, which absorbs H2S being the principal component of the smell of flatus.
In connection with the use of filters there is often a well-known need of measures for effectively preventing blocking of the inlet opening of filters of ostomy appliances. When the inlet opening of the filter is blocked, the gas discharged into the ostomy appliance cause ballooning of the bag being highly undesirable for several reasons.
Ballooning will be embarrassing for the user as the bag will bulge and there is an increased risk of leakage being unacceptable for the user.
However, it has been found in practice that for some ostomates having a very low production of flatus there is a considerable risk that air is vented more quickly from the bag through the filter than the discharge of gas into the bag and hence, a vacuum-like condition is produced in the bag. The consequence may be that due to adhesion between the walls of the receiving bag there is a considerable risk that visceral contents reaching the opening of the stoma will not immediately be able to separate the walls and “fall” into the bottom of the receiving bag but will rather stay and block the entrance to the bag. This situation is highly undesirable as faecal matter may be pressed against the area around the stoma and even beneath the adhesive wafer securing the ostomy appliance to the abdominal wall creating a risk of leakage and having aggressive influence on the skin, or even upwards against the inlet opening of a filter of the bag which will again further increase the risk of blocking of the inlet of the filter which again may result in ballooning and even leakage.
2. Description of the Related Art
At present an ostomate may try to avoid this situation using commercially available separate adhesive labels that may be applied so as to cover the outlet opening of the filter partly or fully. These separate filter labels are, however, not 100% sealing as their primary function is to protect the filter against influence of water while bathing and furthermore, such a label can only be used once. Thus, the ostomate must always carry a minor supply of labels in order to secure the collecting bag against blocking as it is always necessary from time to time to vent the bag in order to avoid ballooning.
European Patent No. EP 0 535 801 discloses an ostomy bag which has two vents one of which is filtered and the other of which is unfiltered. An adhesive strip is used to seal the vents and can be peeled back to open them so that by pulling the walls of the bag apart, air is drawn into the bag. The vent is then closed to trap air in the bag and keep the front wall away from the rear wall in the region of the opening in order to avoid “pancaking”.
Published European Patent Application No. EP 0 985 390 discloses an ostomy appliance having a filtered vent having a plurality of apertures and adhesive sticker means which can be positioned to selectively expose or cover one or more of the plurality of outlets to control the flow rate through the vent. The sticker means may consist of a number of separate sticker segments which can be peeled away to selectively expose one or more exits under each segment. EP 0 985 390 is silent with respect to a sticker having a surface which may be sealed releasably to the wall enabling a placing of the sticker covering the outlet opening to a desired degree and also enabling a detachment and reattachment of the sticker according to the need which renders it possible to adapt the outlet of gas from the bag according to the actual need by relocating the sticker so as to cover more or less of the outlet vent without being dependent on disposable closures.
Thus, there is still a need of a closure which may prevent pancaking by allowing a 100% sealing of the outlet opening of the filter of an ostomy appliance and, at the same time, giving the option of allowing a minor amount of gas to pass out of an ostomy appliance according to need without having to rely on the presence of a supply of disposable closures which may only be used once and which must be disposed of in an acceptable manner.